Power-operated disinfecting pruning shears



June 1952 c. J. JOHNSON 2,600,540

POWER-OPERATED DISINFECTING PRUNING SHEARS f Filed Sept. 3. 1946 27 INVENTOR 3 CIIJ'oknson .26 4M1 mit/ ATTO R N EYS Patented June 17, 1952 POWER-OPERATED DISINFEO'II'JING PRUNING SHEA-RS Charles J. Johnson,

Sacramento, Califl, assignor cf one-half to Frank E. King, Sacramento,

. Calif.

Application September 3, 1946, Serial No. 694,584

' 1 Claim.

This invention relates to, and it is an object to provide, improved pruning shears which are power actuated the invention here being shown as embodied in long reach or pole type pruning shears. I

A further characteristic of the present invention is the novel shear blade assembly and means for power actuating the same; said means including a valve controlled, fluid pressure actuated power cylinder.

An additional characteristic of this invention is the provision of an automatic device on the implement operative to discharge a quantity of liquid disinfectant on each cut as made by the shear blade assembly on a limb.

Another characteristic of the invention resides in the provision of an insulating medium between the shear blade assembly and the remainder of the implement so that if a live wire is accidentally engaged by said assembly, shock cannot be transmitted to the operator.

A further object of the invention is to provide a simple and inexpensive device, and yet one which will be exceedingly effective for the purpose for which it is designed.

These objects are accomplished by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

In the drawings:

Fig. 1 is an elevation, foreshortened, of the improved pruning shears showing the shear blade assembly in closed position.

Fig. 2 is an elevation, foreshortened, of the pruning shears taken from the opposite side; the actuating mechanism being mainly in section.

Fig. 3 is a fragmentary view, partly broken away, showing the pivotal connection between the actuating rod and the shanks of the shear blade assembly.

Referring now more particularly to the characters of reference on the drawings, the implement comprises a hand grip I fixed in connection with, and projecting laterally from, one end of a cylinder 2; such cylinder having an externally threaded, axially projecting boss 3 on its opposite end. A collar 4 connects the boss 3 in axial alinement with an elongated tubular pole 5 which is fitted, at its outer end, with a shear blade assembly, indicated generally at 6.

The shear blade assembly includes a fixed blade I and a cooperating movable blade 8; the latter being pivotally connected by a cross bolt 9 with said fixed blade 1.

The fixed blade 1 includes a substantially V 2 I straight rigid shank I 0 formed with a foot ll having a downwardly extending boss I2 centrally thereon. The boss I2 is fitted in the upper endof the pole 5, and the foot Hand boss l2- are insulated away from said pole by means including a dielectric sleeve l3 interposed between the bossl2 and said pole 5.

The movable blade 8 includes a depending curved rigid shank 14 which intersects the straight shank III of the fixed blade 1; said shanks including therein a curved slot l5 and a' straight slot [6, respectively. Q r

A double-acting piston I1 isfoperativelvdi'sposed in the cylinder 2 and is fixed in connec-' tion with an actuating rod 18 which extends out of the cylinder 2 through a packing gland 19 into the tubular pole 5; said rod extending toa point adjacent the shear blade assembly 6. At its upper end the actuating rod I8 is fitted with a head 20 which carries a fixed, laterally projecting bolt 2| which extends through the slots l5 and'lfi. On the side of the blade assembly opposite the head 20 the bolt 2| carries lock nuts 22, and a roller 23 on said bolt 2| rides 'in the'slots I5 and A dielectric connector 24 is i r'ite'rposed in the actuating rod I8. By reason of the insulation of the shear blade assembly 6 from the pole 5 by means including the dielectric sleeve l3, and the interposition of the dielectric connector 24 in the actuating rod l8, it is impossible for any electric shock to be transmitted to the operator should said shear blade assembly 6 be engaged accidentally with a live wire.

It will be seen that upon reciprocation of the piston I l in the cylinder 2, the blades 1 and 8 will relatively move between a normally open position to a closed position and return, whereby to effect a cutting action. This is accomplished by reason of the fact that when the piston I 1 reciprocates, the head 20 advances and then retracts, causing corresponding shifting movement of the bolt 2| and roller 23. When the roller is so moved in the slots [5 and IS, the shank M, on account of the curvature of its slot, is swung in a direction to cause closing and opening movement of the blade 8 relative to the blade I.

Reciprocation of the piston I! in the cylinder 2 is controlled through the medium of a doubleacting plunger or piston valve unit 25 incorporated in the cylinder 2 along the side thereof adjacent the hand grip I; said valve unit 25 including an exteriorly accessible push button 25. Fluid under pressure is supplied to the valve unit 25 by a flexible conduit 27 which leads into the hand grip I, and such pressure is delivered from within said hand grip into the valve unit 25 through a port 28.

In one position of the valve unit 25 fluid pressure delivers into the cylinder 2 through a duct 29, pressure from the opposite side of the piston then bleeding through .a'duct 30-:out of thecylinder to escape through a port 3 I; In the opposite position of the valve unit 25, fluid pressure delivers through the duct 30 and escapes through the duct 29 into the forward end of the valve unit 25, whence said escaping pressure feeds into a conduit 32. I1 is moving in a direction to-open: the shear. blade assembly.

The conduit 32 leads to a pressure regulating or reducing valve 33 on one. sideof. the pole. 5, from which an outlet conduit" 341eads to a reservoir 35 on the pole, which reservoir is adapted. to contain a quantity of liquid disinfectant. The pressure regulating. valver33 may be of anyv conventional type useful, for the. purpose as. forinstance; that shown. in:the 1946 catalogue of .the- Imperial Co. of.12U-W.est-.Harrison Street, Chi-. cage,- Illinois page 33,. out 80-740 regulator.v Another outlet-conduit 36 leads from. the. pressure regulating valve 33 to a pointonthe fixed blade. I adj acent;. and: for discharge toward, the cuttingedge of said:blade: all-pressure not passed through: the outlet; conduit: 34 flowing. through the; outlet conduit 36. A trigger element: 3.1 clamped between the nuts 22 engages and opens arvalvet 38; arranged: to establish communication between the outlet conduit 34a. of reservoin 35. and conduit 36 intermediate. the ends: of the latter, when'. the 'shear; blade. assembly 6. reaches a=substantially closed position; Thus as each element? is cut by-the. bladeassembly 6,: and at the: momentthe-latter closes, aquantity of. dis.- iniectantais discharged from thereservoir 35 through the. valve 38iinto-the conduit 36- and theneeontoxthecut; the fluid pressure for accomplishing i this action: being. derived, as previouslyindicated;- fromtheexhaust of piston. H as it advances from the position shown in Fig. 2;

Eromtheforeeoing description it will be readily seen thatthere'has been produced such a device This occurs when the-piston 4 as substantially fulfills the objects of the invention as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure-from.the spirit-of -theizinvention; as defined. by the. appended claim.

Having thus described the invention, the following is claimed as new and useful, and upon which Letters Patent are desired:

In: pruning shears having a shear blade unit including a movable blade and means to move saidublade". between open and closed positions, a;. pole depending: from the blade unit, a fluid reservoir secured on the pole intermediate its ends and. adaptedto be maintained under pressure, a conduit leading from the reservoir to a pointadjacent the blade unit for discharge into a cut made thereby, aanormally closed control valve inathe conduit havinganaexposed operating element, and-1a finger. mounted for movement with thermovable' blade arranged to 1 engage. the,- operating element and open the'valve whensaid. blade moves to a closed position.

CHARLES J. JOHNSON.

REFERENCES CITED.

The following. references: are of 1 record: inthe file of this patent:

UNITED STATES PATENTS Number, Name: Date:

379,359 Bosch Mar. 13,1888- 7'73,743 Von Hoffmann Nov. 1, 19.04

1,056,046 Myers Mar. 18, g 1913 1,476,049 Bush ..Dec.r4,..1923: 1,741,172 Huxman .Dec. 31;,1929, 2,075,341. Goodman .Mar. 30,.193'7 2,277,442 Kuhiman Mar. 24,1942 2,366,909 Johnson Jan..9; 1945: 2,446,011 Johnson: July-27,1948 2,462,701.- Wirth; Eeb, 22, 1949.

FOREIGN PATENTS i Number Country: Date Great Britain of 1886 

